Tuesday, November 29, 2016

If you have
small kids, the idea of them someday leaving home is painful and scary in a
way. But then when they reach adolescence and start to be irrational and
dramatic for apparently no reason, and walk dragging their feet all over your
place, the idea of them leaving gets not only reasonable but also urgent J . So, if one thinks of their age when they
finally get independent it might appear to be quite late compared to other mammals.

All mammals
are dependent on their mothers for a species-specific period of time, ranging
from a few weeks to a few years; but have you ever wondered how long do
elephant calves stay with their mothers?

The elephant
calves have extremely emotional brains and need mom in order to learn how to
behave within their own society and to cope with specific situations and
stress. They have shown to share emotions and behavior traits with humans, and
like humans, the elephant calves stay dependent on their mother (and others in
the herd) for survival during quite a long time: after a pregnancy period of about
22 months (my goodness! the longest gestation period in mammals) they start to suckle since they are born until 3.5 – 5 years, and they can even share mom´s milk with a newborn. The elephant calves depend entirely (that is, physically and psychologically)
on their mothers for three to five years. However, the bonds between mother and
offspring remain strong afterwards, and in the case of mother-daughter they
even last a lifetime.

During the infancy, the `mother figure´ is
extremely important. The maternal behavior (the care giving behavior given by
female mammals) includes: suckling, nurturing, providing shelter, passing on
traditions, and protecting from danger among others:

This video
shows a typical `mother behavior´, where the females are protecting the infants from a potential danger (the camera) by pushing them aside with their body and trunk. Like the chimpanzees, allomothers (caring females in the herd other than mothers) can be not only other adult females (frequently called `aunts´), but also young females
and the infant´s own siblings. The chance of taking part in an infant´s
development period is hugely important to these young future mothers, as they
will gather experience for the moment when they have their own offspring. The importance of allomothers is such, that if the biological mother happens to die leaving unweaned offspring, they will do her job (allonurse) by producing milk even if they had no offspring of their own.

This
matriarchal system involves not only the obvious maternal responsibilities, but
also plays a role in protecting the herd, making daily decisions on movements,
feeding and drinking places, etc.

As a curiosity: elephants are thought to be born hairless,
but actually they do have most of their `lanugo´ or embryonal hairs on their
backs and heads after their birth and keep it for some years:

The adolescence occurs at the age of six to
fifteen when they reach sexual maturity. Now is the time when the herds break
and form; young bulls gather in bachelor herds and females stay in the
matriarchal group.

In the case
of adolescent males, this period implies the separation from the matriarchal
herd to join other males; youngs gather together and sometimes they join other
adult males that can teach them. This phase thus implies male encounters,
fights, musth (it usually occurs at the age of 10-12 the first time) and the search for females to mate.

The females,
however, stay in their group where they meet their maternal instincts,
developing social tasks like caring for the infants.

Finally, the adulthood starts at the age of 15-17, when the families are formed. It´s time to settle their role in the matriarchal system (in the case of females), made up by a head female, mothers, daughters, sisters and aunts. Females have a reproductive life very
similar to humans, continuing reproducing until midlife and experiencing a
post-reproductive phase similar to menopause in women. They give
birth to a single calf (twins are very rare) with two to four-year intervals. The moment of the birth
is followed by rumbles and trumpets, gland secretions and really high
excitement performed by other females of the group.

The African elephants are the land mammals with the longest lifespan under ideal circumstances (not being poached for example): they can reach an age of 60 to 70 years…amazing for wild animals!

According to
Weihs (2002), the elephant life stages could be summarized as follows:

How curious
we humans are: we place ourselves right at the top of all living creatures thinking
that we are so different from the others; but if we lowered ourselves to come
down from our throne and have a closer look at other species like elephants and
chimpanzees, we will realize how similar our natures actually are. It´s a good humility
exercise.

Monday, November 21, 2016

The sexual
dimorphism is a condition that some species have when the two sexes show
different characteristics. In some animal species, these differences can be
very obvious (for example in Mandrills), being manifested by color, size,
presence of certain features like breasts, etc.

In the case
of African elephants, however, the sexual dimorphism is unfortunately not so
clear. Even sometimes for the most trained eyes it can be tough to tell the
gender. Even the genitals can be misleading as both penis and vulva hang
ventrally. Besides, the male´s testes are located in the abdominal cavity,
which makes the assumption even harder.

There are
cases when the sex is more than evident:

but If you
don´t get to see an elephant erect, here are some very general tips that will
help tell an African elephant´s gender apart.

Overall body shape: Males are more robust and in general
bigger than females.

Head: an adult male´s head (forehead) is
usually wider than an adult female´s.

Trunk: an adult male´s trunk is pretty thicker/wider
than a female´s, especially the base of the trunk.

Tusks: usually longer and thicker in males than in
females; a broken tusk might be as well the result of a fight between males.

As a curiosity: again Can, our African forest elephant in the
Abidjan zoo, was thought to be a male for 20 years!!, until we saw her
urinating; when males urinate, the penis comes out and then you have a good
chance to claim the sex;

Monday, November 14, 2016

Although there used to exist species of elephants on earth, we can unfortunately confirm
three occurring currently in Asia and Africa:

Elephas maximus (Asian
elephant)

Loxodonta africana (African
bush elephant)

Loxodonta cyclotis (African forest elephant)

Sometimes it might appear easy to
distinguish between all three species, or at least between the African and
Asian sp., but actually it can be sometimes tricky. If you have a look at the
following table, you will notice that in general, African sp. are a bit bigger
and heavier than their Asian relatives. But if you are not in Asia or Africa,
but in front of an elephant far from their natural habitat (like a zoo) this
feature alone can be confusing, as it obviously depends on the individual´s age
and physical condition. So one thing that usually helps is the size of their
ears, and their head´s shape. In African elephants, their ears reach up over
the neck, and the head shape is basically round.

The main morphological differences
between the African and Asian elephant species are:

Loxodonta sp.

Elephas maximus

Weight

4.000-7.000 Kg

3.000-6.000

Height
(shoulder height)

3-4 m.

2-3,5 m.

Skin

wrinkled

Relatively smooth

Ears

Bigger

smaller

Tusks

Existing in both sexes

Females have no tusks or only
rudimentary

Trunk

2 fingertips/ very wrinkled/more
flexible

1 fingertip/less wrinkled/less
flexible

Shape of
the back

Concave

Convex (sometimes even straight)

Toenails

Forelegs: 4 (sometimes 5)

Hind legs: 3 (sometimes 4)

Forelegs: 5

Hind legs: 4 (sometimes 5)

Belly shape

slopes diagonally downwards towards
its hind legs

Round/straight, horizontal

Head shape

round

Two bulges

Interesting as it might be,
yet our concern here is not about how to differentiate between African or Asian
ele. but how to tell apart the two African species.

Just a short summary of
physical African elephant traits:

Loxodontaafricana

Loxodonta cyclotis

Weight

4.000 - 7.000 Kg

2.000
- 4.500 kg

Height
(shoulder height)

3-4 m.

2 - 3 m

Skin

wrinkled/ less and shorter hairs

Smoother/long hairs, long eyelashes

Ears

cuts usually are
individual; the older they get, the more folded the ear can be

shape of the African
continent

cuts usually are individual; the older they get, the more
folded the ear can be

But these are only numbers and approximations, necessary when it comes to taxonomy, but in nature things don´t always work that way; in fact, there´s been controversy between taxonomists when claiming differences between both African species. As a curiosity: years ago, local people and hunters, claimed to exist another species of elephants occurring in Africa, the Pygmy elephant. There was some controversy about this fact, some researchers agreed, some didn´t, and years later those individuals that were seen and thought to be pygmy elephants, happened to be the infants of the African forest species, so the new “discovery” was finally rejected. We have been often asked if there is a difference in behavior between all three species, and honestly, we are never really sure what to say. There are plenty of different opinions: some believe that Asian elephants are thought to be more docile than the African species, others don´t; the Africans are thought to be a bit more “dirty” than the Asians (they like to take their own poo and put it on their backs).
It is also said that the African forest elephants tend to accumulate food on their backs, while the African bush elephants don´t do it that often… and we have witnessed it: see what the lovely forest elephant Can from the Abidjan zoo likes to do with her food:

Call them what you will, we personally don´t mind if they have big or small ears, thin or thick tusks, if they are clean, dirty, docile or fierce…